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Fencer Intel
critical 9.8

CVE-2026-43341 in the critical feed json

net/ipv6: ioam6: prevent schema length wraparound in trace fill

published 6mo ago modified 21d ago also EUVD-2026-28625

cvss
9.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 43%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

net/ipv6: ioam6: prevent schema length wraparound in trace fill

ioam6_fill_trace_data() stores the schema contribution to the trace length in a u8. With bit 22 enabled and the largest schema payload, sclen becomes 1 + 1020 / 4, wraps from 256 to 0, and bypasses the remaining-space check. __ioam6_fill_trace_data() then positions the write cursor without reserving the schema area but still copies the 4-byte schema header and the full schema payload, overrunning the trace buffer.

Keep sclen in an unsigned int so the remaining-space check and the write cursor calculation both see the full schema length.

Patch / fix

  • Linux Linux 5.15.210, 6.1.168, 6.6.134, 6.12.81, 6.18.22, 6.19.12, 7.0
  • linux Debian 12 6.1.170-1
  • linux Debian 13 6.12.85-1
  • linux Debian 14 6.19.12-1

debian advisories DEBIAN-CVE-2026-43341

  • linux Ubuntu 22.04 LTS 5.15.0-185.195
  • linux Ubuntu 24.04 LTS 6.8.0-134.134
  • linux Ubuntu 25.10 6.17.0-40.40
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1111.118
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1060.63
  • linux-aws Ubuntu 25.10 6.17.0-1019.19
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1111.121
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1063.69

ubuntu advisories UBUNTU-CVE-2026-43341

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel RHEL 10.2 6.12.0-211.31.1.el10_2
  • rv RHEL 10.2 6.12.0-211.31.1.el10_2
  • perf RHEL 10.2 6.12.0-211.31.1.el10_2
  • rtla RHEL 10.2 6.12.0-211.31.1.el10_2
  • libperf RHEL 10.2 6.12.0-211.31.1.el10_2
  • kernel-rt RHEL 10.2 6.12.0-211.31.1.el10_2
  • kernel-64k RHEL 10.2 6.12.0-211.31.1.el10_2
  • kernel-core RHEL 10.2 6.12.0-211.31.1.el10_2

red hat advisories RHSA-2026:36541RHSA-2026:33215

  • kernel-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-48.1
  • kernel-source-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-48.1
  • kernel-rt Real Time Module 15 SP7 6.4.0-150700.7.59.2
  • kernel-syms-rt Real Time Module 15 SP7 6.4.0-150700.7.59.1
  • kernel-source-rt Real Time Module 15 SP7 6.4.0-150700.7.59.2
  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.60.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.60.1
  • kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.53.60.1

suse advisories SUSE-SU-2026:22433-1SUSE-SU-2026:22458-1SUSE-SU-2026:2591-1SUSE-SU-2026:2482-1SUSE-SU-2026:22108-1SUSE-SU-2026:22137-1

  • kernel AlmaLinux 10 6.12.0-211.31.1.el10_2
  • rv AlmaLinux 10 6.12.0-211.31.1.el10_2
  • perf AlmaLinux 10 6.12.0-211.31.1.el10_2
  • rtla AlmaLinux 10 6.12.0-211.31.1.el10_2
  • libperf AlmaLinux 10 6.12.0-211.31.1.el10_2
  • kernel-rt AlmaLinux 10 6.12.0-211.31.1.el10_2
  • kernel-64k AlmaLinux 10 6.12.0-211.31.1.el10_2
  • kernel-core AlmaLinux 10 6.12.0-211.31.1.el10_2

almalinux advisories ALSA-2026:36541

Is CVE-2026-43341 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-43341 updated cvss 7.0

kernel: net/ipv6: ioam6: prevent schema length wraparound in trace fill

  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-211.31.1.el10_2, perf 6.12.0-211.31.1.el10_2, rtla 6.12.0-211.31.1.el10_2, python3-perf 6.12.0-211.31.1.el10_2, kernel-devel-matched 6.12.0-211.31.1.el10_2, kernel-64k-devel-matched 6.12.0-211.31.1.el10_2, +7 more
    fixed: vendor fix RHSA-2026:36541
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) rv 6.12.0-55.84.1.el10_0, perf 6.12.0-55.84.1.el10_0, rtla 6.12.0-55.84.1.el10_0, python3-perf 6.12.0-55.84.1.el10_0, kernel-devel-matched 6.12.0-55.84.1.el10_0, kernel-64k-devel-matched 6.12.0-55.84.1.el10_0, +7 more
    fixed: vendor fix RHSA-2026:33215
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-211.31.1.el10_2, kernel-64k 6.12.0-211.31.1.el10_2, kernel-core 6.12.0-211.31.1.el10_2, kernel-tools 6.12.0-211.31.1.el10_2, kernel-modules 6.12.0-211.31.1.el10_2, kernel-64k-core 6.12.0-211.31.1.el10_2, +28 more
    fixed: vendor fix RHSA-2026:36541
  • Red Hat Enterprise Linux BaseOS EUS (v. 10.0) kernel 6.12.0-55.84.1.el10_0, kernel-64k 6.12.0-55.84.1.el10_0, kernel-core 6.12.0-55.84.1.el10_0, kernel-tools 6.12.0-55.84.1.el10_0, kernel-modules 6.12.0-55.84.1.el10_0, kernel-64k-core 6.12.0-55.84.1.el10_0, +27 more
    fixed: vendor fix RHSA-2026:33215
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.31.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.31.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.31.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.31.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.31.1.el10_2
    fixed: vendor fix RHSA-2026:36541
  • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) libperf 6.12.0-55.84.1.el10_0, kernel-debuginfo-common-s390x 6.12.0-55.84.1.el10_0, kernel-debuginfo-common-x86_64 6.12.0-55.84.1.el10_0, kernel-debuginfo-common-aarch64 6.12.0-55.84.1.el10_0, kernel-debuginfo-common-ppc64le 6.12.0-55.84.1.el10_0
    fixed: vendor fix RHSA-2026:33215
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-211.31.1.el10_2, kernel-rt-64k 6.12.0-211.31.1.el10_2, kernel-rt-core 6.12.0-211.31.1.el10_2, kernel-rt-modules 6.12.0-211.31.1.el10_2, kernel-rt-64k-core 6.12.0-211.31.1.el10_2, kernel-rt-debug-core 6.12.0-211.31.1.el10_2, +14 more
    fixed: vendor fix RHSA-2026:36541
  • Red Hat Enterprise Linux Real Time EUS (v. 10.0) kernel-rt 6.12.0-55.84.1.el10_0, kernel-rt-64k 6.12.0-55.84.1.el10_0, kernel-rt-core 6.12.0-55.84.1.el10_0, kernel-rt-modules 6.12.0-55.84.1.el10_0, kernel-rt-64k-core 6.12.0-55.84.1.el10_0, kernel-rt-debug-core 6.12.0-55.84.1.el10_0, +14 more
    fixed: vendor fix RHSA-2026:33215
show 3 more
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-211.31.1.el10_2, kernel-rt-core 6.12.0-211.31.1.el10_2, kernel-rt-modules 6.12.0-211.31.1.el10_2, kernel-rt-debug-core 6.12.0-211.31.1.el10_2, kernel-rt-modules-core 6.12.0-211.31.1.el10_2, kernel-rt-debug-modules 6.12.0-211.31.1.el10_2, +4 more
    fixed: vendor fix RHSA-2026:36541
  • Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0) kernel-rt 6.12.0-55.84.1.el10_0, kernel-rt-kvm 6.12.0-55.84.1.el10_0, kernel-rt-core 6.12.0-55.84.1.el10_0, kernel-rt-modules 6.12.0-55.84.1.el10_0, kernel-rt-debug-kvm 6.12.0-55.84.1.el10_0, kernel-rt-debug-core 6.12.0-55.84.1.el10_0, +6 more
    fixed: vendor fix RHSA-2026:33215
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
total
Assessed
24d ago

Exploit prediction

0.51% chance of exploitation in the next 30 days, higher than 43% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Weakness
  • CWE-190 Integer Overflow or Wraparound
Technology feeds

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.